I just bought a house that has a furnace on its last legs. The house is 1941 masonry in Chicago with 3 floors: finished basement, first floor and a second floor that is a converted attic with vaulted ceilings and gets way too hot. The total square footage is about 900 per floor (so 2700 total)
I am looking at an American Standard AUH1C100A9481A as a replacement (recommended by a HVAC pro).
Is it worth going with 2-stage and how much extra would it be?
Any disadvantages? I hear variable speed units are pretty unreliable and really expensive on repairs.